LOW←TECH MAGAZINE English

Thematic Book Series: Too Much Combustion, Too Little Fire

Tue, 04 Nov 2025 00:00:00 +0000

Image: Book cover.

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For most of history, the multifunctional fire was the only source of energy in the household. It served as a cookstove, toaster, heating device, lighting source, hot water boiler, clothes dryer, and refrigerator, among other functions. During the twentieth century, the fire was replaced by a wide range of appliances plugged into central infrastructures.

In this series of articles, LOW←TECH MAGAZINE critically examines the efficiency, sustainability, health, and safety of the fire and its flame- and smoke-free modern alternatives. What are we saying when we argue that electrical appliances are “better” than a traditional fire?

Contents table

Too Much Combustion, Too Little Fire
Thermo-electric Stoves: Ditch the Solar Panels?
How to Make Biomass Energy Sustainable Again
Well-Tended Fires Outperform Modern Cooking Stoves
If We Insulate Our Houses, Why Not Our Cooking Pots?
Wood Gas Vehicles: Firewood in the Fuel Tank
Medieval Smokestacks: Fossil Fuels in Pre-industrial Times

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Patrons get free access to ebooks, as well as early access to new print books at a reduced price.

Other books in the series

How to build a low-tech internet?, Kris De Decker, Roel Roscam Abbing, Marie Otsuka, 2023. Ebook edition.
How to downsize a transport network?, Kris De Decker, 2023. Ebook edition.
Heating people not spaces, Kris De Decker, 2024. Ebook edition
How circular is the circular economy?, Kris De Decker, 2025. Ebook edition

The Low-tech Magazine archives are also available as a chronological series consisting of four volumes.

Fascine Mattresses: Basketry Gone Wild

Wed, 03 Nov 2021 00:00:00 +0000

Image: Sinking of a fascine mattress for the drainage sluices at Den oever. Source: Dienst Zuiderzeewerken, CC BY 3.0 NL. Date unknown.

Coastal and River Defences

Climate change is an imminent threat to highly populated coastal and river communities worldwide. For centuries, people have built defence structures to prevent floods and erosion: seawalls, bulkheads, breakwaters, groins, levees, dykes, and revetments. Nowadays, we usually build these structures at least partly from energy- and carbon-intensive materials: reinforced concrete (most commonly), geotextiles, steel, wire mesh, asphalt. However, people can and did build very adequate river and coastal defences without adding to environmental destruction in the longer term.

Inspiration comes – not surprisingly – from the Netherlands. The sea has been a threat in the Low Countries since long before climate change. The Dutch built their country partly at the bottom of the sea, drained it with windmills, and surrounded the new land with dykes. The Dutch coast has fine-grained, sandy soil that offers little resistance to the friction of the water. Currents, waves, and propellers of ships scour the bottom and can easily lead to the collapse of dykes, banks, quays, locks, and abutments.

Image: dyke collapse in Zeeland, near Kats on North Beveland, 1966. Public domain.

The Fascine Mattress

With stagnant or slow-flowing fresh or brackish water, planting reeds on the waterline can protect riverbanks. However, this approach doesn’t work with saltwater, nor does it prevent damage from large waves. At least 400 years ago, the Dutch came up with a solution: the fascine mattress. A fascine mattress consists of thousands of fine twigs, mainly from willow trees. These are woven together into a sturdy mat dropped at the bottom of a canal, estuary, or river. A fascine mattress can lay partly on the river-bank or dyke.

Fascine mattresses were often rectangular and of large dimensions: usually between 20 and 30 metres wide and up to 150 metres long (sometimes more). The structures were made on land, towed to their location, and then sunk to the bottom by weighting them with rubble. Everything happened by hand. Nearby coppice plantations supplied the wood for braiding the mattresses.

Image: The making of a fascine mattress, Haringvliet, 1956. Public domain.

Life Expectancy: Centuries

It’s not clear when exactly the Dutch started using fascine mattresses. The oldest image is a 1676 painting by Matthias Withoos, which illustrates the repair of a dyke. However, there are references to brushwood constructions in hydraulic engineering already in the sixteenth century. Many fascine mattresses remain functional today, centuries after their construction. Willow wood becomes rock-hard underwater and almost doesn’t deteriorate. Research in the late 1960s showed that most fascine mattresses submerged for more than 100 years – some dating from the early 1820s – remained intact.

We don’t know how many fascine mattresses are still performing their duties at the bottom of the Dutch waters, but they are basically everywhere. Most data is available from the period following World War II when the Dutch used the technology on a large scale. In 1953, catastrophic flooding hit the Netherlands. That led to the Delta Works, a series of ambitious construction works to protect the land from the sea.

Image: Fascine mattresses in the biesbosch, 1968. Public Domain.

Fascine mattresses were an essential part of this plan. For example, between 1960 and 1966, the Dutch added 200,000 m2 of fascine mattresses in the Wadden area (a group of islands in the north). Between 1954 and 1967, during works on the rivers throughout the country, they sank 1,200,000 m2 fascine mattresses to the bottom.

Braiding a Fascine Mattress

Making a fascine mattress was a craft that mainly involved knotting and braiding. In tidal areas, the Dutch braided fascine mattresses on mudflats that were dry at low tide. This meant that the work had to happen quickly. When the high tide came in again, the structure started floating – and it had to be sturdy enough not to drift apart. Finishing the fascine mattress could happen during the next low tide or even while the structure was floating.

The craftsmen started weaving brushwood into bundles or strips called fascines (“wiepen” in Dutch). Fascines were up to 50m long, had a diameter of about 30-50 cm, and were tied together with thin twigs. The fascines served to build a lower framework, which formed the basis of the entire structure. The bundles were superimposed crosswise about a meter apart and secured with rope and a pole at the crossings.

On top of this framework came a 30-40 cm “filling” of two layers of brushwood across each other. In between these came a reed layer, which made the fascine mattress sand proof. Next, an upper framework of fascines was built, identical to the lower framework, on top of the “filling”. The men then lashed the whole thing to the posts. It took about six men to build 100m2 fascine mattress.

Image: A fascine mattress. By Jan Muijs, Rijkswaterstaat, 1974, CC BY 3.0 nl.

Image: Drawing of a classical fascine mattress made out of willow wood for bed protection of watercourse. Source: Hollands' Rijshout, Van Breen (1920).

Image: Making fascines, 1945. Unknown photographer / Anefo, CC0, via Wikimedia Commons

Image: Making fascines, 1952. Harry Pot / Anefo, CC0, via Wikimedia Commons.

Image: Transporting fascines, 1953. Joop van Bilsen / Anefo, CC0, via Wikimedia Commons.

Image: Braiding fascine mattresses, 1956. Harry Pot / Anefo, CC0, via Wikimedia Commons.

Fences

Next, the craftsmen braided fences on top of a fascine mattress by weaving more brushwood around the poles at the points where the fascines crossed and which protruded well above the upper framework. These fences further reinforced the structure and prevented rubble from rolling off the mattress. That was a risk during the sinking of the fascine mattress. The enclosure also performed its duties when the fascine mattress rested on a steep slope, for instance, a dyke. Smaller stone rubble could also be carried along by the current – fences prevented this. Finally, the men fitted a fascine mattress with drag props (arrangements of seven piles securely tying the ropes) for towing purposes.

Image: Braiding fences on top of a fascine mattress, 1950. By van Oorschot / Anefo, CC0, via Wikimedia Commons.

Image: Braiding the fences. Source: [Zink- en aanverwante werken, benevens het hoe en de wijze waarop](https://repository.tudelft.nl/islandora/object/uuid%3A1ed44c19-ee2a-450d-bc3c-6e377cae54ef), B. Hakkeling, 1970.

Sinking a Fascine Mattress

Once the craftsmen had towed a fascine mattress to its destination and moored it, they sank the structure to the bottom. To this end, the workers weighted the fascine mattress with stone and rubble. This heavy work happened manually. Rows of craftsmen took place on gangways, passing 10 to 30 kg stones one by one. Workers with wheelbarrows transported the rubble from land by wheelbarrows or scooped it straight from a boat onto the fascine mattress.

At sea, one square metre of fascine mattress required roughly 200 kg of stones for sinking. Most weight was placed on the edges to prevent the fascine mattress from tipping over while sinking. Once the structure had reached the bottom, they added another 1,000 kg of heavier stones. On rivers it took less weight: only around 120 kilograms for sinking a fascine mattress and roughly 300 kilograms for keeping it in place. Finding enough stones was a lot more problematic than finding brushwood because they had to be brought in by ship from far away.

Fascine mattresses could only be sunken in a calm sea with little current, so timing was crucial. The slack tide, a period of a few minutes between low and high tide, was exploited to the maximum, even if that meant that work had to be done partly at night.

Image: Workers install fascine matttresses for the construction of locks in the Haringvliet near Hellevoetsluis, 1956. By Anefo, CC0.

Image: Sinking a fascine mattress, 1968. By Nationaal Archief, CC0.

Image: Reinforcing the Vlissingen boulevard, 1958. By Anefo, CC0.

Image: Reinforcing the dyke near Ouwerkerk on Duiveland, 1953. By Joop van Bilsen / Anefo, CC0.

Image: Sinking a fascine mattress. Source: [Zink- en aanverwante werken, benevens het hoe en de wijze waarop](https://repository.tudelft.nl/islandora/object/uuid%3A1ed44c19-ee2a-450d-bc3c-6e377cae54ef), B. Hakkeling, 1970.

Image: Preparing the sinking of a fascine mattress. Source: [Holland’s rijshout](https://repository.tudelft.nl/islandora/object/uuid%3A72029c69-9567-4ad9-8883-ff428cf7d68b), L.G. van Breen, 1920.

Image: Anchoring a fascine mattress. Note the drag prop in the foreground. Joop van Bilsen / Anefo, CC0.

Overlapping Fascine Mattresses

Landing a fascine mattress in the right place was a challenge. It was difficult to sink them with precision. According to some sources, there was often 2-5 metres of space planned between adjacent fascine mattresses. Overlapping structures were to be avoided because the current could overturn the upper piece.

However, Gerrit Jan Schiereck, a retired professor in hydraulic engineering and a former employee of the Dutch public works department, disagrees with this advice: “Contrary to what some books say, it was necessary for fascine mattresses to partly overlap each other”. ¹

Not all fascine mattresses were rectangles. When connecting to existing works, in river bends, and in the case of other irregularities, the structures could take the form of a trapezium or an irregular quadrangle. However, pieces with indented corners were avoided where possible.

Image: Badly dropped fascine mattresses in the bend of a river. Source: [Zink- en aanverwante werken, benevens het hoe en de wijze waarop](https://repository.tudelft.nl/islandora/object/uuid%3A1ed44c19-ee2a-450d-bc3c-6e377cae54ef), B. Hakkeling, 1970.

Image: A collection of fascine mattresses. [Holland’s rijshout](https://repository.tudelft.nl/islandora/object/uuid%3A72029c69-9567-4ad9-8883-ff428cf7d68b), L.G. van Breen, 1920.

Tidal Coppice Plantations

The use of fascine mattresses was closely linked to large-scale brushwood production on coppice plantations. As we saw in a previous article, our forebears harvested wood by lopping trees rather than chopping them. The Dutch coppice plantations – the “grienden” – stand out because of their “wet” soils: high river levels or tidal action occasionally flooded the land. Unlike most other tree species, willow tolerates saltwater and (temporarily) wet feet. As such, the coppice plantations could use land that was not suitable for agriculture.

In 1915, roughly 14,000 hectares (140 km2) of forest in the Netherlands consisted of tidal or river coppice plantations, compared to 85,000 hectares of “normal” coppice plantations, and 155,000 hectares of tall forest. Most lay along estuaries outside the dykes and in the river areas of South Holland and North Brabant. The largest complex was in the Biesbosch. More than 200 different types of willow trees were grown in tidal and river coppice plantations. On impoverished soils, the Dutch planted alder trees between the willow trees. The falling leaves of the alder fertilised the soils and increased the lifespan and production of the willow trees.

Often, a quay surrounded tidal coppice plantations. This kept the water out during a normal tide. The plantation only flooded during storm surges in winter. Valves ensured that the water drained slowly enough to allow the sludge to settle, fertilising the soil. Ditches traversed the plantations and served for drainage – stagnant water was harmful to the trees. The workers also used the narrow canals transporting the brushwood out of the plantations by boats. River coppice plantations were inside the dykes. Here, the groundwater level – influenced by nearby rivers – determined the environment for the trees.

Harvesting the wood was just as labour-intensive as braiding the fascine mattresses. Maintenance was undertaken entirely by hand and concentrated in the winter months. The plantation workers chopped brushwood after the leaves had fallen and tied the branches into bundles. They also put new cuttings in the ground, dredged the ditches, and removed the wood. Most coppice plantation workers were day laborers at a time of the year when there was very little agricultural work. They most often slept in small shelters or on small boats on the plantations. ²

Image: Outer dyke willow field on the Oude Maas (Carnisse Grienden). By Ceinturion, (CC BY-SA 3.0).

Image: The Biesbosch in 1908. Source: [Wilgenkartering in de Brabantse, Sliedrechtse en Dordtse Biesbosch, 2012-2013](http://www.ecologischadviesbureaumaes.nl/429_I.pdf). Nationaal Park de Biesbosch, 2014.

Image: A tidal coppice plantation (Anna-Jacominaplaat) in 1950. Source: [Wilgenkartering in de Brabantse, Sliedrechtse en Dordtse Biesbosch, 2012-2013](http://www.ecologischadviesbureaumaes.nl/429_I.pdf). Nationaal Park de Biesbosch, 2014.

Image: Ditch in a tidal coppice plantation (1930-1950). Source: [Wilgenkartering in de Brabantse, Sliedrechtse en Dordtse Biesbosch, 2012-2013](http://www.ecologischadviesbureaumaes.nl/429_I.pdf). Nationaal Park de Biesbosch, 2014.

Image: A worker's hut on a mound. Source: Regionaal Archief Dordrecht. (CC-BY-SA 4.0).

Houseboat in a tidal coppice plantation. Source: Regionaal Archief Dordrecht. (CC-BY-SA 4.0).

Evolution in the 1960s

Following the catastrophic floods of the 1950s, the Dutch set up a working group to find labour-saving and production-enhancing working methods. The weaving of the fascines, a job that accounted for about a third of all hours in making a fascine mattress, was the first process to be mechanised. A “fascine machine” – running on a 2 HP diesel engine – appeared in 1956. It could make 10,000 fascines per week, supplying enough material for 2,300 m2 of fascine mattresses. From the 1950s, the Dutch also used cranes and vibrating feeders for moving the rubble, and they built wharves to braid the fascine mattresses on large slopes next to the water. That made the construction of a fascine mattress independent of the tides and allowed to organise the work better. The techniques for sinking the structures also evolved.

Finally, the invention of geotextiles as adequate sand filters lowered the need for coppiced wood. This was crucial, because the existing production fields of willow in the country at the time could not supply the quantities needed for the Delta Project. The Dutch tidal and river coppice plantations served different purposes, and fascine mattresses only formed a small market. Much more important were the weaving of baskets and crates, and especially the building of hoops for making herring barrels, an important export product in the Netherlands at the time. Indeed, the Dutch used the waste materials from the hoop-making process to braid fascine mattresses. However, after World War I, iron straps and other packaging materials supplanted hoop-making from the market. Furthermore, fossil fuels made it easier to keep polders dry, so less and less land was available for coppice plantations. Of the 14,000 hectares of tidal and river coppice plantations in 1915, only 2,000 hectares remained in 1983.

The use of traditional fascine mattresses – without geotextiles – disappeared almost completely. However, they are still in use in nature reserves, and have seen renewed interest lately. Producing steel, concrete, and plastic releases carbon emissions and creates other forms of pollution too. On the other hand, traditional fascine mattresses extract carbon from the atmosphere and store it on the seafloor for a couple of centuries – without any pollution or fossil fuels.

Thanks to Gerrit Jan Schiereck, Bart Schultz, and Alice Essam.

References:

De Bruin, Dick, and Bart Schultz. “A simple start with far‐reaching consequences.” Irrigation and Drainage: The journal of the International Commission on Irrigation and Drainage 52.1 (2003): 51-63.

Zink- en aanverwante werken, benevens het hoe en de wijze waarop, B. Hakkeling, 1970.

JW van Westen, Ontwerp en uitvoering van zinkwerken, 1969.

Holland’s rijshout, L.G. van Breen, 1920.

J.A.M. Schepers, Een landelijk overzicht van de grienden, 1988

Getijdenbossen, F.W. Rappard, 1971

Rijshout-, riet- en stroconstructies, J.C Visser 1954

Stroomzinken 1967-1968, H.Y. Wenning

De teelt van griend- en teenhout in nederland en het naburige vlaanderen. DWP Wisboom van Giessendam, 1878.

Geschiedenis van de techniek in nederland. De wording van een moderne samenleving. 1800-1890, deel III. H.W. Lintsen, 1993.

Wilgenkartering in de Brabantse, Sliedrechtse en Dordtse Biesbosch, 2012-2013. Nationaal Park de Biesbosch, 2014.

Phone call on 2 November 2021. ↩︎
As far as I could find out, the large fascine mattress is almost exclusively a Dutch technology. However, Dutch engineers like Johannis de Rijke also introduced the fascine mattress in Japan during the Meiji period (1868-1912). Here, it was made from bamboo. Some years ago, the Japanese still used the technology in the Hokuriku region. River coppice plantations also existed in present-day Belgium (around Bornem) and Poland, but these plantations only supplied basketry materials. ↩︎

How to Make Biomass Energy Sustainable Again

Sun, 20 Sep 2020 00:00:00 +0000

Image: Pollarded trees in Germany. Image: René Schröder (CC BY-SA 4.0).

How is Cutting Down Trees Sustainable?

Advocating for the use of biomass as a renewable source of energy – replacing fossil fuels – has become controversial among environmentalists. The comments on the previous article, which discussed thermoelectric stoves, illustrate this:

“As the recent film Planet of the Humans points out, biomass a.k.a. dead trees is not a renewable resource by any means, even though the EU classifies it as such.”
“How is cutting down trees sustainable?”
“Article fails to mention that a wood stove produces more CO2 than a coal power plant for every ton of wood/coal that is burned.”
“This is pure insanity. Burning trees to reduce our carbon footprint is oxymoronic.”
“The carbon footprint alone is just horrifying.”
“The biggest problem with burning anything is once it’s burned, it’s gone forever.”
“The only silly question I can add to to the silliness of this piece, is where is all the wood coming from?”

In contrast to what the comments suggest, the article does not advocate the expansion of biomass as an energy source. Instead, it argues that already burning biomass fires – used by roughly 40% of today’s global population – could also produce electricity as a by-product, if they are outfitted with thermoelectric modules. Nevertheless, several commenters maintained their criticism after they read the article more carefully. One of them wrote: “We should aim to eliminate the burning of biomass globally, not make it more attractive.”

Apparently, high-tech thinking has permeated the minds of (urban) environmentalists to such an extent that they view biomass as an inherently troublesome energy source – similar to fossil fuels. To be clear, critics are right to call out unsustainable practices in biomass production. However, these are the consequences of a relatively recent, “industrial” approach to forestry. When we look at historical forest management practices, it becomes clear that biomass is potentially one of the most sustainable energy sources on this planet.

Coppicing: Harvesting Wood Without Killing Trees

Nowadays, most wood is harvested by killing trees. Before the Industrial Revolution, a lot of wood was harvested from living trees, which were coppiced. The principle of coppicing is based on the natural ability of many broad-leaved species to regrow from damaged stems or roots – damage caused by fire, wind, snow, animals, pathogens, or (on slopes) falling rocks. Coppice management involves the cutting down of trees close to ground level, after which the base – called the “stool” – develops several new shoots, resulting in a multi-stemmed tree.

Image: A coppice stool. Credit: Geert Van der Linden.

Image: A recently coppiced patch of oak forest. Credit: Henk vD. (CC BY-SA 3.0)

Image: Coppice stools in Surrey, England. Credit: Martinvl (CC BY-SA 4.0)

When we think of a forest or a tree plantation, we imagine it as a landscape stacked with tall trees. However, until the beginning of the twentieth century, at least half of the forests in Europe were coppiced, giving them a more bush-like appearance. ¹ The coppicing of trees can be dated back to the stone age, when people built pile dwellings and trackways crossing prehistoric fenlands using thousands of branches of equal size – a feat that can only be accomplished by coppicing. ²

Maps: The approximate historical range of coppice forests in the Czech Republic (above) and in Spain (below). Source: \"Coppice forests in Europe\", see [^1]

Ever since then, the technique formed the standard approach to wood production – not just in Europe but almost all over the world. Coppicing expanded greatly during the eighteenth and nineteenth centuries, when population growth and the rise of industrial activity (glass, iron, tile and lime manufacturing) put increasing pressure on wood reserves.

Short Rotation Cycles

Because the young shoots of a coppiced tree can exploit an already well-developed root system, a coppiced tree produces wood faster than a tall tree. Or, to be more precise: although its photosynthetic efficiency is the same, a tall tree provides more biomass below ground (in the roots) while a coppiced tree produces more biomass above ground (in the shoots) – which is clearly more practical for harvesting. ³ Partly because of this, coppicing was based on short rotation cycles, often of around two to four years, although both yearly rotations and rotations up to 12 years or longer also occurred.

Images: Coppice stools with different rotation cycles. Credit: Geert Van der Linden.

Because of the short rotation cycles, a coppice forest was a very quick, regular and reliable supplier of firewood. Often, it was cut up into a number of equal compartments that corresponded to the number of years in the planned rotation. For example, if the shoots were harvested every three years, the forest was divided into three parts, and one of these was coppiced each year. Short rotation cycles also meant that it took only a few years before the carbon released by the burning of the wood was compensated by the carbon that was absorbed by new growth, making a coppice forest truly carbon neutral. In very short rotation cycles, new growth could even be ready for harvest by the time the old growth wood had dried enough to be burned.

In some tree species, the stump sprouting ability decreases with age. After several rotations, these trees were either harvested in their entirety and replaced by new trees, or converted into a coppice with a longer rotation. Other tree species resprout well from stumps of all ages, and can provide shoots for centuries, especially on rich soils with a good water supply. Surviving coppice stools can be more than 1,000 years old.

Biodiversity

A coppice can be called a “coppice forest” or a “coppice plantation”, but in reality it was neither a forest nor a plantation – perhaps something in between. Although managed by humans, coppice forests were not environmentally destructive, on the contrary. Harvesting wood from living trees instead of killing them is beneficial for the life forms that depend on them. Coppice forests can have a richer biodiversity than unmanaged forests, because they always contain areas with different stages of light and growth. None of this is true in industrial wood plantations, which support little or no plant and animal life, and which have longer rotation cycles (of at least twenty years).

Image: Coppice stools in the Netherlands. Credit: K. Vliet (CC BY-SA 4.0)

Image: Sweet chestnut coppice at Flexham Park, Sussex, England. Credit: Charlesdrakew, public domain.

Our forebears also cut down tall, standing trees with large-diameter stems – just not for firewood. Large trees were only “killed” when large timber was required, for example for the construction of ships, buildings, bridges, and windmills. ⁴ Coppice forests could contain tall trees (a “coppice-with-standards”), which were left to grow for decades while the surrounding trees were regularly pruned. However, even these standing trees could be partly coppiced, for example by harvesting their side branches while they were alive (shredding).

Multipurpose Trees

The archetypical wood plantation promoted by the industrial world involves regularly spaced rows of trees in even-aged, monocultural stands, providing a single output – timber for construction, pulpwood for paper production, or fuelwood for power plants. In contrast, trees in pre-industrial coppice forests had multiple purposes. They provided firewood, but also construction materials and animal fodder.

The targeted wood dimensions, determined by the use of the shoots, set the rotation period of the coppice. Because not every type of wood was suited for every type of use, coppiced forests often consisted of a variety of tree species at different ages. Several age classes of stems could even be rotated on the same coppice stool (“selection coppice”), and the rotations could evolve over time according to the needs and priorities of the economic activities.

Image: A small woodland with a diverse mix of coppiced, pollarded and standard trees. Credit: Geert Van der Linden.

Coppiced wood was used to build almost anything that was needed in a community. ⁵ For example, young willow shoots, which are very flexible, were braided into baskets and crates, while sweet chestnut prunings, which do not expand or shrink after drying, were used to make all kinds of barrels. Ash and goat willow, which yield straight and sturdy wood, provided the material for making the handles of brooms, axes, shovels, rakes and other tools.

Young hazel shoots were split along the entire length, braided between the wooden beams of buildings, and then sealed with loam and cow manure – the so-called wattle-and-daub construction. Hazel shoots also kept thatched roofs together. Alder and willow, which have almost limitless life expectancy under water, were used as foundation piles and river bank reinforcements. The construction wood that was taken out of a coppice forest did not diminish its energy supply: because the artefacts were often used locally, at the end of their lives they could still be burned as firewood.

Image: Harvesting leaf fodder in Leikanger kommune, Norway. Credit: Leif Hauge. Source: [^19]

Coppice forests also supplied food. On the one hand, they provided people with fruits, berries, truffles, nuts, mushrooms, herbs, honey, and game. On the other hand, they were an important source of winter fodder for farm animals. Before the Industrial Revolution, many sheep and goats were fed with so-called “leaf fodder” or “leaf hay” – leaves with or without twigs. ⁶

Elm and ash were among the most nutritious species, but sheep also got birch, hazel, linden, bird cherry and even oak, while goats were also fed with alder. In mountainous regions, horses, cattle, pigs and silk worms could be given leaf hay too. Leaf fodder was grown in rotations of three to six years, when the branches provided the highest ratio of leaves to wood. When the leaves were eaten by the animals, the wood could still be burned.

Pollards & Hedgerows

Coppice stools are vulnerable to grazing animals, especially when the shoots are young. Therefore, coppice forests were usually protected against animals by building a ditch, fence or hedge around them. In contrast, pollarding allowed animals and trees to be mixed on the same land. Pollarded trees were pruned like coppices, but to a height of at least two metres to keep the young shoots out of reach of grazing animals.

Illustration: Different ways of lopping trees. Credit: Helen J. Read, see [^1]

Image: Pollarded trees in Segovia, Spain. Credit: [Ecologistas en Acción](https://www.ecologistasenaccion.org/35724/).

Wooded meadows and wood pastures – mosaics of pasture and forest – combined the grazing of animals with the production of fodder, firewood and/or construction wood from pollarded trees. “Pannage” or “mast feeding” was the method of sending pigs into pollarded oak forests during autumn, where they could feed on fallen acorns. The system formed the mainstay of pork production in Europe for centuries. ⁷ The “meadow orchard” or “grazed orchard” combined fruit cultivation and grazing – pollarded fruit trees offered shade to the animals, while the animals could not reach the fruit but fertilised the trees.

Image: Forest or pasture? Something in between. A \"dehesa\" (pig forest farm) in Spain. Credit: Basotxerri (CC BY-SA 4.0).

Image: Cattle grazes among pollarded trees in Huelva, Spain. (CC BY-SA 2.5)

Image: A meadow orchard surrounded by a living hedge in Rijkhoven, Belgium. Credit: Geert Van der Linden.

While agriculture and forestry are now strictly separated activities, in earlier times the farm was the forest and vice versa. It would make a lot of sense to bring them back together, because agriculture and livestock production – not wood production – are the main drivers of deforestation. If trees provide animal fodder, meat and dairy production should not lead to deforestation. If crops can be grown in fields with trees, agriculture should not lead to deforestation. Forest farms would also improve animal welfare, soil fertility and erosion control.

Line Plantings

Extensive plantations could consist of coppiced or pollarded trees, and were often managed as a commons. However, coppicing and pollarding were not techniques seen only in large-scale forest management. Small woodlands in between fields or next to a rural house and managed by an individual household would be coppiced or pollarded. A lot of wood was also grown as line plantings around farmyards, fields and meadows, near buildings, and along paths, roads and waterways. Here, lopped trees and shrubs could also appear in the form of hedgerows, thickly planted hedges. ⁸

Image: Hedge landscape in Normandy, France, around 1940. Credit: W Wolny, public domain.

Image: Line plantings in Flanders, Belgium. Detail from the Ferraris map, 1771-78.

Although line plantings are usually associated with the use of hedgerows in England, they were common in large parts of Europe. In 1804, English historian Abbé Mann expressed his surprise when he wrote about his trip to Flanders (today part of Belgium): “All fields are enclosed with hedges, and thick set with trees, insomuch that the whole face of the country, seen from a little height, seems one continued wood”. Typical for the region was the large number of pollarded trees. ⁸

Like coppice forests, line plantings were diverse and provided people with firewood, construction materials and leaf fodder. However, unlike coppice forests, they had extra functions because of their specific location. ⁹ One of these was plot separation: keeping farm animals in, and keeping wild animals or cattle grazing on common lands out. Various techniques existed to make hedgerows impenetrable, even for small animals such as rabbits. Around meadows, hedgerows or rows of very closely planted pollarded trees (“pollarded tree hedges”) could stop large animals such as cows. If willow wicker was braided between them, such a line planting could also keep small animals out. ⁸

Image: Detail of a yew hedge. Credit: Geert Van der Linden.

Image: A hedgerow. Credit: Geert Van der Linden.

Image: Pollarded tree hedge in Nieuwekerken, Belgium. Credit: Geert Van der Linden.

Image: Coppice stools in a pasture. Credit: Jan Bastiaens.

Trees and line plantings also offered protection against the weather. Line plantings protected fields, orchards and vegetable gardens against the wind, which could erode the soil and damage the crops. In warmer climates, trees could shield crops from the sun and fertilize the soil. Pollarded lime trees, which have very dense foliage, were often planted right next to wattle-and-daub buildings in order to protect them from wind, rain and sun. ¹⁰

Dunghills were protected by one or more trees, preventing the valuable resource from evaporating due to sun or wind. In the yard of a watermill, the wooden water wheel was shielded by a tree to prevent the wood from shrinking or expanding in times of drought or inactivity. ⁸

Image: A pollarded tree protects a water wheel. Credit: Geert Van der Linden.

Image: Pollarded lime trees protect a farm building in Nederbrakel, Belgium. Credit: Geert Van der Linden.

Location Matters

Along paths, roads and waterways, line plantings had many of the same location-specific functions as on farms. Cattle and pigs were hoarded over dedicated droveways lined with hedgerows, coppices and/or pollards. When the railroads appeared, line plantings prevented collisions with animals. They protected road travellers from the weather, and marked the route so that people and animals would not get off the road in a snowy landscape. They prevented soil erosion at riverbanks and hollow roads.

All functions of line plantings could be managed by dead wood fences, which can be moved more easily than hedgerows, take up less space, don’t compete for light and food with crops, and can be ready in a short time. ¹¹ However, in times and places were wood was scarce a living hedge was often preferred (and sometimes obliged) because it was a continuous wood producer, while a dead wood fence was a continuous wood consumer. A dead wood fence may save space and time on the spot, but it implies that the wood for its construction and maintenance is grown and harvested elsewhere in the surroundings.

Image: Pollarded tree hedge in Belgium. Credit: Geert Van der Linden.

Local use of wood resources was maximised. For example, the tree that was planted next to the waterwheel, was not just any tree. It was red dogwood or elm, the wood that was best suited for constructing the interior gearwork of the mill. When a new part was needed for repairs, the wood could be harvested right next to the mill. Likewise, line plantings along dirt roads were used for the maintenance of those roads. The shoots were tied together in bundles and used as a foundation or to fill up holes. Because the trees were coppiced or pollarded and not cut down, no function was ever at the expense of another.

Nowadays, when people advocate for the planting of trees, targets are set in terms of forested area or the number of trees, and little attention is given to their location – which could even be on the other side of the world. However, as these examples show, planting trees closeby and in the right location can significantly optimise their potential.

Shaped by Limits

Coppicing has largely disappeared in industrial societies, although pollarded trees can still be found along streets and in parks. Their prunings, which once sustained entire communities, are now considered waste products. If it worked so well, why was coppicing abandoned as a source of energy, materials and food? The answer is short: fossil fuels. Our forebears relied on coppice because they had no access to fossil fuels, and we don’t rely on coppice because we have.

Our forebears relied on coppice because they had no access to fossil fuels, and we don’t rely on coppice because we have

Most obviously, fossil fuels have replaced wood as a source of energy and materials. Coal, gas and oil took the place of firewood for cooking, space heating, water heating and industrial processes based on thermal energy. Metal, concrete and brick – materials that had been around for many centuries – only became widespread alternatives to wood after they could be made with fossil fuels, which also brought us plastics. Artificial fertilizers – products of fossil fuels – boosted the supply and the global trade of animal fodder, making leaf fodder obsolete. The mechanisation of agriculture – driven by fossil fuels – led to farming on much larger plots along with the elimination of trees and line plantings on farms.

Less obvious, but at least as important, is that fossil fuels have transformed forestry itself. Nowadays, the harvesting, processing and transporting of wood is heavily supported by the use of fossil fuels, while in earlier times they were entirely based on human and animal power – which themselves get their fuel from biomass. It was the limitations of these power sources that created and shaped coppice management all over the world.

Image: Harvesting wood from pollarded trees in Belgium, 1947. Credit : Zeylemaker, Co., Nationaal Archief (CCO)

Image: Transporting firewood in the Basque Country. Source: Notes on pollards: best practices' guide for pollarding. Gipuzkoaka Foru Aldundía-Diputación Foral de Giuzkoa, 2014.

Wood was harvested and processed by hand, using simple tools such as knives, machetes, billhooks, axes and (later) saws. Because the labour requirements of harvesting trees by hand increase with stem diameter, it was cheaper and more convenient to harvest many small branches instead of cutting down a few large trees. Furthermore, there was no need to split coppiced wood after it was harvested. Shoots were cut to a length of around one metre, and tied together in “faggots”, which were an easy size to handle manually.

It was the limitations of human and animal power that created and shaped coppice management all over the world

To transport firewood, our forebears relied on animal drawn carts over often very bad roads. This meant that, unless it could be transported over water, firewood had to be harvested within a radius of at most 15-30 km from the place where it was used. ¹² Beyond those distances, the animal power required for transporting the firewood was larger than its energy content, and it would have made more sense to grow firewood on the pasture that fed the draft animal. ¹³ There were some exceptions to this rule. Some industrial activities, like iron and potash production, could be moved to more distant forests – transporting iron or potash was more economical than transporting the firewood required for their production. However, in general, coppice forests (and of course also line plantings) were located in the immediate vicinity of the settlement where the wood was used.

In short, coppicing appeared in a context of limits. Because of its faster growth and versatile use of space, it maximised the local wood supply of a given area. Because of its use of small branches, it made manual harvesting and transporting as economical and convenient as possible.

Can Coppicing be Mechanised?

From the twentieth century onwards, harvesting was done by motor saw, and since the 1980s, wood is increasingly harvested by powerful vehicles that can fell entire trees and cut them on the spot in a matter of minutes. Fossil fuels have also brought better transportation infrastructures, which have unlocked wood reserves that were inaccessible in earlier times. Consequently, firewood can now be grown on one side of the planet and consumed at the other.

The use of fossil fuels adds carbon emissions to what used to be a completely carbon neutral activity, but much more important is that it has pushed wood production to a larger – unsustainable – scale. [14] Fossil fueled transportation has destroyed the connection between supply and demand that governed local forestry. If the wood supply is limited, a community has no other choice than to make sure that the wood harvest rate and the wood renewal rate are in balance. Otherwise, it risks running out of fuelwood, craft wood and animal fodder, and it would be abandoned.

Image: Mechanically harvested willow coppice plantation. Shortly after coppicing (right), 3-years old growth (left). Credit: Lignovis GmbH (CC BY-SA 4.0).

Likewise, fully mechanised harvesting has pushed forestry to a scale that is incompatible with sustainable forest management. Our forebears did not cut down large trees for firewood, because it was not economical. Today, the forest industry does exactly that because mechanisation makes it the most profitable thing to do. Compared to industrial forestry, where one worker can harvest up to 60 m3 of wood per hour, coppicing is extremely labour-intensive. Consequently, it cannot compete in an economic system that fosters the replacement of human labour with machines powered by fossil fuels.

Coppicing cannot compete in an economic system that fosters the replacement of human labour with machines powered by fossil fuels

Some scientists and engineers have tried to solve this by demonstrating coppice harvesting machines. ¹⁴ However, mechanisation is a slippery slope. The machines are only practical and economical on somewhat larger tracts of woodland (>1 ha) which contain coppiced trees of the same species and the same age, with only one purpose (often fuelwood for power generation). As we have seen, this excludes many older forms of coppice management, such as the use of multipurpose trees and line plantings. Add fossil fueled transportation to the mix, and the result is a type of industrial coppice management that brings few improvements.

Image: Coppiced trees along a brook in 's Gravenvoeren, Belgium. Credits: Geert Van der Linden.

Sustainable forest management is essentially local and manual. This doesn’t mean that we need to copy the past to make biomass energy sustainable again. For example, the radius of the wood supply could be increased by low energy transport options, such as cargo bikes and aerial ropeways, which are much more efficient than horse or ox drawn carts over bad roads, and which could be operated without fossil fuels. Hand tools have also improved in terms of efficiency and ergonomics. We could even use motor saws that run on biofuels – a much more realistic application than their use in car engines. ¹⁵

The Past Lives On

This article has compared industrial biomass production with historical forms of forest management in Europe, but in fact there was no need to look to the past for inspiration. The 40% of the global population consisting of people in poor societies that still burn wood for cooking and water and/or space heating, are no clients of industrial forestry. Instead, they obtain firewood in much of the same ways that we did in earlier times, although the tree species and the environmental conditions can be very different. ¹⁶

A 2017 study calculated that the wood consumption by people in “developing” societies – good for 55% of the global wood harvest and 9-15% of total global energy consumption – only causes 2-8% of anthropogenic climate impacts. ¹⁷ Why so little? Because around two-thirds of the wood that is harvested in developing societies is harvested sustainably, write the scientists. People collect mainly dead wood, they grow a lot of wood outside the forest, they coppice and pollard trees, and they prefer the use of multipurpose trees, which are too valuable to cut down. The motives are the same as those of our ancestors: people have no access to fossil fuels and are thus tied to a local wood supply, which needs to be harvested and transported manually.

Image: African women carrying firewood. (CC BY-SA 4.0)

These numbers confirm that it is not biomass energy that’s unsustainable. If the whole of humanity would live as the 40% that still burns biomass regularly, climate change would not be an issue. What is really unsustainable is a high energy lifestyle. We can obviously not sustain a high-tech industrial society on coppice forests and line plantings alone. But the same is true for any other energy source, including uranium and fossil fuels.

Multiple references: Unrau, Alicia, et al. Coppice forests in Europe. University of Freiburg, 2018. // Notes on pollards: best practices’ guide for pollarding. Gipuzkoako Foru Aldundia-Diputación Foral de Gipuzkoa, 2014. // A study of practical pollarding techniques in Northern Europe. Report of a three month study tour August to November 2003, Helen J. Read. // Aarden wallen in Europa, in “Tot hier en niet verder: historische wallen in het Nederlandse landschap”, Henk Baas, Bert Groenewoudt, Pim Jungerius and Hans Renes, Rijksdienst voor het Cultureel Erfgoed, 2012. ↩︎
Logan, William Bryant. Sprout lands: tending the endless gift of trees. WW Norton & Company, 2019. ↩︎
Holišová, Petra, et al. “Comparison of assimilation parameters of coppiced and non-coppiced sessile oaks”. Forest-Biogeosciences and Forestry 9.4 (2016): 553. ↩︎
Perlin, John. A forest journey: the story of wood and civilization. The Countryman Press, 2005. ↩︎
Most of this information comes from a Belgian publication (in Dutch language): Handleiding voor het inventariseren van houten beplantingen met erfgoedwaarde. Geert Van der Linden, Nele Vanmaele, Koen Smets en Annelies Schepens, Agentschap Onroerend Erfgoed, 2020. For a good (but concise) reference in English, see Rotherham, Ian. Ancient Woodland: history, industry and crafts. Bloomsbury Publishing, 2013. ↩︎ ↩︎ ↩︎ ↩︎
While leaf fodder was used all over Europe, it was especially widespread in mountainous regions, such as Scandinavia, the Alps and the Pyrenees. For example, in Sweden in 1850, 1.3 million sheep and goats consumed a total of 190 million sheaves annually, for which at least 1 million hectares deciduous woodland was exploited, often in the form of pollards. The harvest of leaf fodder predates the use of hay as winter fodder. Branches could be cut with stone tools, while cutting grass requires bronze or iron tools. While most coppicing and pollarding was done in winter, harvesting leaf fodder logically happened in summer. Bundles of leaf fodder were often put in the pollarded trees to dry. References: Logan, William Bryant. Sprout lands: tending the endless gift of trees. WW Norton & Company, 2019. // A study of practical pollarding techniques in Northern Europe. Report of a three month study tour August to November 2003, Helen J. Read. // Slotte H., “Harvesting of leaf hay shaped the Swedish landscape”, Landscape Ecology 16.8 (2001): 691-702. ↩︎
Wealleans, Alexandra L. “Such as pigs eat: the rise and fall of the pannage pig in the UK”. Journal of the Science of Food and Agriculture 93.9 (2013): 2076-2083. ↩︎
This information is based on several Dutch language publications: Handleiding voor het inventariseren van houten beplantingen met erfgoedwaarde. Geert Van der Linden, Nele Vanmaele, Koen Smets en Annelies Schepens, Agentschap Onroerend Erfgoed, 2020. // Handleiding voor het beheer van hagen en houtkanten met erfgoedwaarde. Thomas Van Driessche, Agentschap Onroerend Erfgoed, 2019 // Knotbomen, knoestige knapen: een praktische gids. Geert Van der Linden, Jos Schenk, Bert Geeraerts, Provincie Vlaams-Brabant, 2017. // Handleiding: Het beheer van historische dreven en wegbeplantingen. Thomas Van Driessche, Paul Van den Bremt and Koen Smets. Agentschap Onroerend Erfgoed, 2017. // Dirkmaat, Jaap. Nederland weer mooi: op weg naar een natuurlijk en idyllisch landschap. ANWB Media-Boeken & Gidsen, 2006. // For a good source in English, see: Müller, Georg. Europe’s Field Boundaries: Hedged banks, hedgerows, field walls (stone walls, dry stone walls), dead brushwood hedges, bent hedges, woven hedges, wattle fences and traditional wooden fences. Neuer Kunstverlag, 2013. // If line plantings were mainly used for wood production, they were planted at some distance from each other, allowing more light and thus a higher wood production. If they were mainly used as plot boundaries, they were planted more closely together. This diminished the wood harvest but allowed for a thicker growth. ↩︎ ↩︎ ↩︎ ↩︎
In fact, coppice forests could also have a location-specific function: they could be placed around a city or settlement to form an impenetrable obstacle for attackers, either by foot or by horse. They could not easily be destroyed by shooting, in contrast to a wall. Source: ⁵ ↩︎
Lime trees were even used for fire prevention. They were planted right next to the baking house in order to stop the spread of sparks to wood piles, haystacks and thatched roofs. Source: ⁵ ↩︎
The fact that living hedges and trees are harder to move than dead wood fences and posts also has practical advantages. In Europe until the French era, there was no land register and boundaries where physically indicated in the landscape. The surveyor’s work was sealed with the planting of a tree, which is much harder to move on the sly than a pole or a fence. Source: ⁵ ↩︎
And, if it could be brought in over water from longer distances, the wood had to be harvested within 15-30 km of the river or coast. ↩︎
Sieferle, Rolf Pieter. The Subterranean Forest: energy systems and the industrial revolution. White Horse Press, 2001. ↩︎
Vanbeveren, S.P.P., et al. “Operational short rotation woody crop plantations: manual or mechanised harvesting?” Biomass and Bioenergy 72 (2015): 8-18. ↩︎
However, chainsaws can have adverse effects on some tree species, such as reduced growth or greater ability to transfer disease. ↩︎
Multiple sources that refer to traditional forestry practices in Africa: Leach, Gerald, and Robin Mearns. Beyond the woodfuel crisis: people, land and trees in Africa. Earthscan, 1988. // Leach, Melissa, and Robin Mearns. “The lie of the land: challenging received wisdom on the African environment.” (1998) // Cline-Cole, Reginald A. “Political economy, fuelwood relations, and vegetation conservation: Kasar Kano, Northerm Nigeria, 1850-1915.” Forest & Conservation History 38.2 (1994): 67-78. ↩︎
Multiple references: Bailis, Rob, et al. “Getting the number right: revisiting woodfuel sustainability in the developing world.” Environmental Research Letters 12.11 (2017): 115002 // Masera, Omar R., et al. “Environmental burden of traditional bioenergy use.” Annual Review of Environment and Resources 40 (2015): 121-150. // Study downgrades climate impact of wood burning, John Upton, Climate Central, 2015. ↩︎